The horizontally folding implement herein described is similar in many respects to the implement of copending application Ser. No. 825,903, filed Aug. 19, 1977, now abandoned, as a continuation of Ser. No. 690,945, filed May 28, 1976, now abandoned, both of such applications being in the names of Adee, et al, carrying a title "Fold-Back Implement Frame Having Angle Adjustment," and assigned to the assignee of the present invention.
The implement of that application has its tool beams connected to the central fore-and-aft tongue or frame via special pivot assemblies that provide for both horizontal swinging of the beams between their working and transport positions and for limited vertical swinging movement to accommodate changes in ground contour. While it is, of course, necessary and desirable for the implement to have the ability to flex vertically as terrain variations are encountered, it has been found that such flexure also can create problems if not properly controlled.
In this regard, and as one example of the type of problem that can arise, consider that there is substantial side thrust inwardly along the line of discs carried by the beams as the discs engage and work the ground. Such inward thrust creates a moment about the horizontal pivot of a tool beam, thus tending to raise the pivot at the inner end of the beam. If for any reason the beam is raised slightly such as upon encountering high ground relative to that encountered by the opposite beam, there is a tendency for this upward moment to keep the beam raised, even after the terrain causing the rise has been passed. In other words, the moment resists return of the beam back down to its proper position.